Rail heating method



Nov. 17, 1936. R. E. FRICKEY I 2,060,985

RAIL HEATING METHOD 4 Filed May 21, 1934 Patented Nov. 17, 1936 UNITED STATES UUS!! Uil PATENT OFFICE RAIL HEATING METHOD Royal E. Frickey, San Francisco, Calif., assigner to Welding Service, Inc., San Francisco, Calif., a corporation of California Application May 21, 1934, Serial No. 726,631

4 Claims.

This invention relates generally to the heating of railroad rails in rail treatment processes, where the heated area is subsequently chilled to effect hardening.

In co-pending application Serial No. 660,544, led March 13, 1933, there is disclosed a novel rail treatment process for the hardening of railroad rails, in which a limited area of the upper surface of the rail is heated to an elevated temperature by traversing an electric arc over the same, after which the heated area is chilled to effect hardening. Because of the relatively high temperature of an electric arc, and the localized heating caused by the same, there is a tendency for the arc to burn the surface of the rail over which it is traversing. There is also a tendency for the electric arc to be unstable and erratic in its operation. Burning of the upper surface of the rail is obviously undesirable, particularly since it may mar or pit the upper surface of the rail to a detrimental degree, and since scale or like evidence of burning must be cleaned away before contacting the heated area with a chilling medium. Lack of stability and erratic operation of the arc are likewise undesirable, because of the operating diiculties which are involved in the event the arc is extinguished, and because lack of stability is generally accompanied by ineicient transfer of heat.

It is an object of the present invention to provide an improved method of heating rails by an electric arc, which will minimize burning of the surface of the rail and which will cause the arc to be stabilized and uniform in its operation.

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth in detail in conjunction with the accompanying drawing.

Fig. 1 is a transverse cross-sectional view illustrating apparatus such as can be used in carrying out my method.

Fig. 2 is a cross-sectional detail taken along the line 2-2 of Fig. 1.

In the drawing there is disclosed a portion of the rail heating apparatus utilized in the process disclosed and claimed in said co-pending application Serial No. 660,544 and likewise disclosed in application Serial No. 666,528, led April 17, 1933. Briefly, this apparatus consists of an electric are I0, arranged to operate upon the upper surface of a railroad rail II. To afford a suitable enclosure for the arc, I have shown a box I2 having an open bottom and adapted to rest upon the rail. The top of this box is enclosed by a movable cover I3, which serves to carry the electrode holder I4. Arm I6 serves to connect the holder and the cover to suitable actuating mechanism, whereby the electrode is rapidly traversed over the area being heated, in directions both laterally and longitudinally of the rail. Such traversing movement can be conveniently accomplished by rapidly reciprocating the electrode laterally of the rail, While at the same time effecting reciprocation longitudinally of the rail. With such traversing movement, the arc established between the lower end of the electrode and the upper surface of the rail traces intersecting zigzag paths, so that the heat from the arc is distributed over all points of the area being heated. To minimize concentration of heat and to enable a greater power input to the arc, magnetic means Il is shown for spreading the arc fan shaped. As shown in Fig. 2, the upper surfaces of rail ends at a rail joint are being heated preparatory to a hardening operation.

In applying the present invention, I apply over the area to be heated a material containing an ionizing medium, prior to the striking of the arc. Thereafter, during the heating operation this material influences operation of the arc, to minimize burning of the upper surface of the rail and to cause stable arc operation. While the material can be applied to the upper surface of the rail in the form of a paste, it is more conveniently applied in the form of a granular powder which can be sprinkled upon the rail before the arc is struck.

A material which has given good results is as follows:

Percent Potassium ferro-cyanide 45 Sodium chloride 30 Sodium carbonate 'l Calcium carbonate 9 Charcoal 9 (Percentages are by weight.)

The above material is a homogeneous mixture in the form of a granular powder. A thin layer of this composition can be sprinkled over the area to be heated, and after striking the arc it will not be immediately blown out of the enclosure.

The principal ionizing medium of the above material is potassium ferro-cyanide, which has a marked effect upon stabilizing the arc, and which also minimizes burning of the upper surface of the rail. In fact, I have utilized this ingredient of itself, with considerable success. The remainder of the ingredients, however, are deemed de- 55 llUUl sirable in order to minimize evolution of poisonous gases, and in order to facilitate maintenance of a reducing atmosphere. A reducing atmosphere tends to minimize burning of the rail metal and to avoid carbon impoverishment of the layer of metal being heated.

I claim:

1. In a method of heating railroad rails preparatory to hardening by chilling, spreading a material over a limited area of the upper surface of the rail to be heated, the material consisting of a mixture of potassium ferro-cyanide, sodium chloride, sodium carbonate, calcium carbonate and charcoal, the potassium ferro-cyanide being the major constituent, and then traversing an electric arc over said area.

2. In a method of heating railroad rails preparatory to hardening by chilling, the step of traversing an electric arc over the surface to be heated in the presence of an alkali metal cyanide,

to cause the arc to be stabilized and to prevent injury to the surface of the rail.

3. In a method of heating railroad rails preparatory to hardening by chilling, spreading a material over a limited area of the upper surface of the rail to be heated, the material containing an alkali metal cyanide, and then traversing an electric arc over said area, the alkali metal cyanide serving to cause the arc to be stabilized Without imparting hardening agents to the rail metal.

4. In a method of heating railroad rails preparatory to hardening by chilling, sprinkling a granulated powder over a limited area of the upper surface of the rail to be heated, the powder containing an alkali metal cyanide, and then traversing an electric arc over said area, the alkali metal cyanide serving to cause the arc to be stabilized without imparting hardening agents to the rail metal.

ROYAL E. FRICKEY. 

